A Trial to Assess Brexpiprazole Versus Placebo for the Treatment of Acute Manic Episodes, Associated With Bipolar I Disorder

Inclusion Criteria: * Male or female participants, ages 18 to 65 years, inclusive, at the time of informed consent. * Participants willing to discontinue all prohibited medications to meet protocol-required washouts prior to and during the trial period. * Participants with a Diagnostic \& Statistical Manual on Mental Disorders, 5th Edition (DSM-5) diagnosis of bipolar I disorder displaying an acute manic episode with or without mixed features requiring hospitalization. Diagnosis confirmed by the MINI International Neuropsychiatric Interview (MINI) and a history of at least one previous manic episode with or without mixed features with manic symptoms of sufficient severity to require one of the following interventions: hospitalization or treatment with a mood stabilizer, or treatment with an antipsychotic agent. "Require" was defined as an intervention that occurred rather than one that was recommended. * Young-mania rating scale (YMRS) score of ≥ 24 at screening and baseline Exclusion Criteria: * Sexually active male or women of childbearing potential (WOCBP) who did not agree to practice 2 different methods of birth control or remain abstinent during the trial and for 30 days after the last dose of investigational medicinal product (IMP). * Females who were breastfeeding and/or who had a positive pregnancy test result prior to receiving trial medication. * Participants considered unresponsive to clozapine or who were only responsive to clozapine. * Participants with a his…